--- What happened?
--- I am under the weather. I think I should go to see a doctor.
A:feel very sad
B:don't feel well
C:feel comfortable
如图,小明在做“探究凸透镜成像规律”的实验时,所用凸透镜焦距为15cm.
下列命题正确的是( )
某饭店请你推荐一幅宋代城市风俗画作装饰,你觉得最合适的是( )
有关生物进化理论的说法不正确的是( )